LU-5971 llite: merge ccc_io and vvp_io

LU-5971 llite: merge ccc_io and vvp_io

Move the contents of struct vvp_io into struct ccc_io, delete the
former, and rename the latter to struct vvp_io. Rename various ccc_io
related functions to use vvp rather than ccc.

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Change-Id: I6200f1a5ff4d639d547bd45f91e146dbcc80fe6d
Reviewed-on: http://review.whamcloud.com/13351
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Lai Siyao <lai.siyao@intel.com>
Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>